Method of and means for twisting



Feb. 26, 1935. L, J, ODOWD- 1,992,627

METHOD OF AND MEANS FOR TWISTING Filed Aug. 21, 195i (INVENTOR LESLIE J-awa /,0

3 gb igmw fzrwswm ATTORN EYS Patented Feb. 26, 1935 UNITED STATES PATENTOFFICE Canada, assignor to Celanese Corporation of America, acorporation of Delaware Application August 21, 1931, Serial No. 558,475

low tenacity by means of a fiyer or analogous twisting device.

An object of my invention is to twist yarns in a very economical andefflcient manner. A further object of my invention is to provide meansfor employing a fiyer twisting device to impart high twist to yarns offine denier and/or low tenacity. Other objects of my invention willappear from the following detailed description.

When attempts are made to twist yarns made of artificial filaments andparticularly yarns of fine denier by means of a fiyer twister, ithasbeen found that the yarns tend to break or be damaged so that so manyinterruptions in the operations occur and so much supervision isrequired that the twisting operation by means of a fiyer cannot becarried out with complete commercial success. I have found that this isdue to the fact that in previous apparatus for fiyer twisting, the guideeye for the yarn leaving the fiyer has been placed vertically above theaxis of the vertical spindle upon which the supply or winding-01f bobbinis mounted and this results in the yarn being subjected to such strainduring the twisting process that frequent breakages or other damages tothe yarn occur. I have discovered that if such guide or centering eye isplaced at some distance away from the line extending vertically from theaxis of such spindle, a great deal of the strain or tension on the yarnis eliminated, so that it is possible to twist artificial yarns of finedenier and/or low tenacity by a fiyer process emciently and at low cost.

In accordance with my invention 1 twist yarn by drawing yarn at asuitable linear speed from a supply bobbin or other package that ismounted on a rapidly rotating spindle that is equipped with a fiyer orsimilar acting device through which the yarn passes, and then causingthe same to pass through a point that is spaced from a line that is anextension of the axis of the spindle of the take ofi package, prior towinding the yarn onto the take up bobbin or package.

v This invention is applicable for imparting twist of any degree, but isparticularly suited for imparting high twist to yarns for makingso-called crepe yarns such as are used for the preparation of crepe deChine, georgette, crepe marocain, etc.

Whilethis invention is applicable to the twisting of yarns of all kindswhether made of natural fibres or of artificial filaments, it isparticularly applicable for the twisting of yarns of fine denier and/orlow tenacity made of artificial filaments particularly cellulose acetateor other organic derivatives of cellulose such as organic esters ofcellulose and ethers of cellulose. Examples of other organic esters ofcellulose are cellulose formate, cellulose propionate and cellulosebutyrate while examples of ethers of cellulose are ethyl cellulose,methyl cellulose and benzyl cellulose. This invention is also useful forthe twisting of yarn made of reconstituted cellulose such as may be madeby the viscose, cuprammonium or Chardonnet process.. Composite yarns ofvarious kinds, as for example yarns combining cellulose acetate or othersynthetic. yarn and natural silk or other natural fibers, or yarncombining two or more synthetic fibers may be twisted by my process.

The centering eye through which the yarn passes may be displaced in anydirection, that is to say, the yarn may be caused to pass in front of aline drawn through the axis of the twisting spindle, or behind it, or tothe left of it or to the right of it, or in any other position not onthe direct line passing through the axis of the twisting spindle. As tothe extent'of displacement of the centering eye from the normalposition, this depends on circumstances and is governed by the distanceof the centering eye from the spindle, the denier of the yarn, theweight of the fiyer, and the tension which it is desired that the yarnshould sustain in twisting. In practice the required distance isdetermined by atrial under actual working conditions, the centering eyeor its support being moved until the desired tension is obtained.

The displacement of the guide or centering eye to a position which isnot vertically above the winding oil spindles results in the reductionof the excessive tensions normally developed in fiyer twisting so thatby my invention breakage of yarns is substantially completelyeliminated, and accordingly makes possible the commercially successfultwisting of fine denier yarns of cellulose acetate or other fine denierartificial yarns or other yarns of low tenacity by a fiyer process,-aresult heretofore impossible. By my invention fine denier celluloseacetate yarns can be twisted by a fiyer process very efilciently and atlow cost. Fine denier mixed yarns containing cellulose acetate and silkor other natural fibres can be twisted by my process with lesssuspensions of operation and with remarkably high efliciency. I,

.In order further to illustrate my invention but without being limitedthereto reference is had to the accompanying drawing, wherein Figure 1is an elevation partly in section showing my invention as applied to aflyer twisting device, and

Figure 2 is a cross section along the line 2-2 of Figure 1 showing thecentering eye.

On the drawing the supply bobbing 1 is, mounted on the rotating verticalspindle 2 and the yarn Y is drawn from the bobbin 1 through the flyer 3and the centering or guide eye 4 located in a special manner, as will beexplained later, tothe take up or winding bobbin 5. While a figure 8flyer is shown on the drawing, this invention is applicable to the useof other fiyers, such as the figure 4" flyer, the 2 arm straight flyer,or the Universal flyer. The bobbin 5 is driven by the rotating corkroller 6 which engages its surface frictionally and the yarn is guidedonto this bobbin by means of the traverse guide '7 on the traverse bar8.

In order to reduce the rather excessive stresses on the yarn produced bythe ordinary arrangement of the prior flyer twisting device, I place thecentering or guide eye 4 at a point which is laterally of the lineextending vertically from the axis of the spindle 2 of the take offbobbin 1. By placing the centering eye 4 in this position rather thanvertically above the spindle 2, the stresses and strains on the yarnbeing twisted are greatly reduced so that the great advantages pointedout above may be attained. The centering eye 4 is mounted on a rail 9.In order to permit the necessary displacement of the centering eye 4,the rail 9 may have a slot 10 at its point of support and the bolt 11passes through this slot to permit the securing of the rail in thedesired position.

In operation the take off or supply bobbin 1 is rotated at the requiredhigh speed, while the yarn Y is being drawn oil? by the take-up bobbin5. This rotation oi. the bobbin 1 with the assistance of the flyer 3,imparts twist to the yarn in the course of its passage from the supplybobbin to the take-up bobbin, as is well understood. The centering eye4, being displaced from a line extending vertically from the spindle 2,causes the yarn to pass through the flyer in such a manner that it isnot subjected to such great stresses and strains as it would be if itwere conducted, after leaving the fiyer, through a point verticallyabove the spindle 2, so that the fine denier yarns or yarns of lowtenacity may be twisted economically and with great efliciency by meansof the flyer twisting device.

It is to be understood that the foregoing detailed description is givenmerely by way of fllustration and that many variations may be madetherein without departing from the spirit of my invention.

Having described my invention, what I claim and desire to secure byLetters Patents is:

1. Process of twisting yarn which comprises drawing yarn of fine denierand containing cellulose acetate filaments from a package rotating at arelatively high speed, passing said yarn through an unwinding devicewhich is movable under the influence of tension in the yarn and isadapted to assist the twisting and to guide the yarn to a point abovesaid package, which point is substantially in a line passing through andcoincident with the vertical axis of the package, and then causing theyarn to pass, from said device to a winding device, in an angular paththrough a fixed point which is spaced from said line passing through thevertical axis of the package 2. Apparatus for twisting yarn comprising arotating vertical spindle adapted to support a yarn package from whichthe yarn is drawn oil, a winding device adapted to wind the yarn wherebytwist is imparted to the yarn, unwinding means, movable under theinfluence of tension in the yarn, for assisting the twisting of the yarnand for guiding said yarn to a point above said spindle, which point issubstantially in a line passing through and coincident with the verticalaxis of said spindle, and a guide for the yarn between the last namedmeans and the winding device, said guide being placed at a fixed pointspaced from said line passing through the vertical axis of the spindlewhereby the yarn is caused to travel in an angular path from saidtwisting means to said winding device.

3. Apparatus for twisting yarn comprising a rotating vertical spindleadapted to support a yarn package from which the yarn is drawn oil, awinding device adapted to wind the yarn whereby twist is imparted to theyarn, a flyer mounted on said spindle, means on said flyer for guidingsaid yarn to a point above said spindle, which point is substantialy ina line passing through and coincident with the vertical axis of saidspindle, and a guide for the yarn between the flyer and the windingdevice, saidguide being placed at a. fixed point spaced from said linepassing through the vertical axis oi. the spindle whereby the yarniscaused to travel in an annular path from said flyer to said windingdevice.

LESLIE JAMES O'DOWD.

